>>48566464Slowpoke’s instincts dominate its physiology.
Kantonian Slowpoke fishes and resides in water because it needs to eat, so it does not manifest its lamest psychic powers.
The Water type Shellder dominates the Slowpoke when it evolves into either Slowbro or Slowking, so that is why they are primarily Water.
For Galarian Slowbro and Galarian Slowking, the Shellder dominates as well, but due to the spices on the Galarian Slowpoke, the Shellder transforms into a Poison type and injects toxins into the Galarian Slowpoke.
>>48563927The Ice type characteristics that Galarian Mr. Mime develop overcome its Psychic ones. It manipulates ice to form barriers of light. Tap dancing is huge in Galar and the region is cold by default. Galarian Mime and Mr. Rime practice tap dancing in the cold and on ice floors. The ones that survive in these conditions become Ice types. Pantomiming is no longer a thing so the Fairy characteristic drops. At the same time, the Pokémon is more obsessed about dancing in the cold than creating barriers.